title: UHPLC determination of catechins for the quality control of green tea.
abstract: An ultra-high performance liquid chromatography (UHPLC) with UV detection method was developed for the fast quantitation of the most represented and biologically important green tea catechins and caffeine. UHPLC system was equipped with C18 analytical column (50mm×2.1mm, 1.8μm), utilizing a mobile phase composed of pH 2.5 triethanolamine phosphate buffer (0.1M) and acetonitrile in a gradient elution mode; under these conditions six major catechins and caffeine were separated in a 3min run. The method was fully validated in terms of precision, detection and quantification limits, linearity, accuracy, and it was applied to the identification and quantification of catechins and caffeine present in green tea infusions. In particular, commercially available green tea leaves samples of different geographical origin (Sencha, Ceylon Green and Lung Ching) were used for infusion preparations (water at 85°C for 15min). The selectivity of the developed UHPLC method was confirmed by comparison with UHPLC-MS/MS analysis. The recovery of the main six catechins and caffeine on the three analyzed commercial tea samples ranged from 94 to 108% (n=3). Limits of detection (LOD) were comprised in the range 0.1-0.4μgmL(-1). An orthogonal micellar electrokinetic (MEKC) method was applied for comparative purposes on selectivity and quantitative data. The combined use of the results obtained by the two techniques allowed for a fast confirmation on quantitative characterization of commercial samples.
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, via Belmeloro 6, 40126 Bologna, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Naldi
authors.forename: Jessica
authors.initials: J
authors.lastname: Fiori
authors.forename: Roberto
authors.initials: R
authors.lastname: Gotti
authors.forename: Aurélie
authors.initials: A
authors.lastname: Périat
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Veuthey
authors.forename: Davy
authors.initials: D
authors.lastname: Guillarme
authors.forename: Vincenza
authors.initials: V
authors.lastname: Andrisano
mesh_terms: D002110:Caffeine / Q000032:analysis / Q000737:chemistry; D002138:Calibration; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D005843:Geography; D007700:Kinetics; D013058:Mass Spectrometry; D008823:Micelles; D010936:Plant Extracts; D011786:Quality Control; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D013662:Tea / Q000737:chemistry*; D013805:Theobromine / Q000737:chemistry; D013806:Theophylline / Q000737:chemistry
chemical_list: D008823:Micelles; D010936:Plant Extracts; D013662:Tea; D002110:Caffeine; C417939:catechin gallate; D002392:Catechin; C045651:epigallocatechin gallate; D013806:Theophylline; D013805:Theobromine
keywords: (+)-catechin; (−)-catechin gallate; (−)-epicatechin; (−)-epicatechin gallate; (−)-epigallocatechin; (−)-epigallocatechin-gallate; (−)-gallocatechin; (−)-gallocatechin-gallate; C; CF; CG; Catechins; EC; ECG; EGC; EGCG; GC; GCG; Green tea; MEKC; TB; TF; UHPLC–MS; UHPLC–UV; caffeine; theobromine; theophylline